Peptides and their use to ameliorate cell death

ABSTRACT

There is disclosed novel peptides, fragments or analogues thereof and polynucleotides encoding the same, obtained from streptokinase suitable for use in the amelioration of cell death and methods related thereto.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. application Ser. No.08/759,599, filed Dec. 5, 1996, U.S. Pat. No. 5,917,013, whichapplication claims the benefit of provisional Application No.60/008,233, filed Dec. 6, 1995, both of which are incorporated byreference in their entirety.

TECHNICAL FIELD

The present invention generally relates to novel compositions andmethods for use thereof in the amelioration of cell death. Morespecifically, the present invention is directed to peptides obtainedfrom streptokinase, as well as derivatives and analogs thereof, andtheir use in the amelioration of apoptosis and/or necrosis.

BACKGROUND OF THE INVENTION

Cell death occurs in both normal human development and in pathologicalconditions. Two kinds of cell death have been recognized: apoptosis andnecrosis. Briefly, apoptosis, or programmed cell death, is a naturalprocess that is triggered by specific biological events and proceeds bywell-defined mechanisms. Apoptosis occurs by compaction and convolutionof the nuclear chromatin into dense masses, fragmentation of thenucleus, and blebbing of the plasma membrane, ultimately resulting incell death. Even though 50% of an organism's cells are experiencing somestage of apoptosis at any given time, the process is observable in onlyabout 0.1% of those cells.

Necrosis, on the other hand, is easily observed. Necrosis results fromsevere or sudden insult, for example as a result of physical trauma,anoxia, hyperthermia or chemically induced damage. Briefly, necrosis istypified by early changes in the structure and function of themitochondria. When the mitochondria are unable to provide energy to thecell, the cell can no longer maintain homeostasis. The plasma membranethen loses its ability to regulate osmotic pressure and the cell swellsand bursts, spilling its contents into the surrounding tissue andprovoking an inflammatory response. In cases of severe injury orbacterial infection, this response can result in additional tissuedamage. Cell necrosis is associated with diseases that result from theacute interruption of blood flow to any organ of the body. For example,the interruption of blood flow to the heart, brain, or kidney mayproduce, by way of example, myocardial infarction, cerebral infarction,or renal infarction, respectively. Cell necrosis is also associated withthe toxic effects of bacteria and chemicals and bacterial or viralinfections of any organ in the body.

Apoptosis appears to be genetically regulated. However, apoptosis can beinduced by exposing cells to radiation, heat, cytotoxic agents, andabnormal changes in cellular biology. The mitochondria may also beinvolved in apoptosis. Excessive cell death may result in cripplingdegenerative disorders, for example, the annihilation of vital CD4⁺T-lymphocytes in HIV infected patients; the elimination of neurons, andother cell types, following ischemia and reperfusion; and thedestruction of cells after exposure to ionizing or ultraviolet radiationin the treatment of neoplastic disorders. These disorders are thought tostem from ectopically programmed cell death, e.g., metabolic orinfective factors that induce the apoptosis. Too little cell death canresult in proliferative disorders, such as neoplastic disorders orautoimmune disease when a particular immune cell lives beyond itsappropriate life span.

One common trigger of apoptosis in the acquisition of these disorders isoxidative stress, which causes the production of free radicals. Freeradicals are highly reactive molecular species which interact with awide variety of naturally occurring cellular components. Exposure tofree radical leads to cumulative damage to cellular components and,ultimately, to the tissue itself.

A variety of factors may increase the free radical concentration andoxidative stress, thereby rendering the warm-blooded animal susceptibleto cell death and its associated disorders. Such factors includeconsiderations of genetics, nutritional status, exposure to drugtherapy, drug metabolism, disease, and environmental factors. A changein any one of these factors may result in a failure of the body'sdefensive mechanisms and lead to cell death. Cellular damage has beeninvoked as a possible etiology in the development of variousdegenerative disorders, including, by way of example, cardiovasculardisease, autoimmune disorders, arthritis, cancer, pancreatitis,hepatoxicity, cataracts, macular degeneration, accelerated aging,Parkinson's disease, Alzheimer's disease, and the like.

The present invention discloses novel compositions and methods for theamelioration of cell death, and further provides other relatedadvantages.

SUMMARY OF THE INVENTION

As noted above, the present invention provides compositions and methodsfor the amelioration of cell death due to necrosis or apoptosis. Withinone aspect of the present invention peptides obtained from astreptokinase are provided (as well as fragments, derivatives, andanalogues thereof), which are capable of ameliorating cell death.

Within a related aspect of the invention, isolated polynucleotidesequences are provided which encode the aforementioned peptide, or afragment or analogue thereof. Within certain embodiments of theinvention, the polynucleotide sequence may be operably linked to apromoter within an expression vector, in order to allow expression ofthe polynucleotide sequence. Also provided are host cells which containsuch expression vectors.

Other aspects of the present invention provide pharmaceuticalcompositions, comprising a peptide obtained from a streptokinase (aswell as fragments, derivatives, and analogues thereof), in a suitablepharmaceutical, physiological, or medicamentally acceptable excipient ordiluent.

Within yet another aspect of the present invention, methods ofameliorating cell death are provided comprising the general step oftreating a warm-blooded animal by administering a therapeuticallyeffective amount of a compound, as described above, such that cell deathis ameliorated. In this regard the compound may be either a peptide orpeptide derivative, a peptide analog, or, a nucleic acid molecule whichdirects the expression of the peptide or peptide derivative. In oneembodiment of this aspect, the warm-blooded animal is suffering from adisorder selected from the group consisting of neurodegenerativedisorders, cardiovascular diseases, immune diseases, neoplasticdisorders, inflammatory disorders, myelodegenerative disease, viraldisease and degenerative diseases of any organ.

Neurodegenerative disorders include, by way of example, Parkinson's,Alzheimer's, Huntington's, cerebellar degeneration, and FALS.

Cardiovascular diseases include, by way of example, hypertensive heartdisease, heart failure, atherosclerosis, myocardial infarction,congestive heart disease and myocardial reperfusion injury.

Immune diseases include, by way of example, autoimmune disease,AIDS/HIV, and immune deficiencies. Autoimmune diseases include, by wayof example, rheumatoid arthritis, systemic lupus erythematosus,insulin-dependent diabetes mellitus, myasthenia gravis,glomerulonephritis, lupus, pernicious anemia, dermatomyositis, enythemanodosum, Sjögren's syndrome, temporal arteritis, Wegener'sgranulomatosis, antiphospholipid syndrome, and autoimmunepolyarthritides.

Neoplastic disorders include, by way of example, leukemia, sarcomas,myelomas, carcinomas, neuromas, melanoma, cancers of the breast, brain,colon, cervix, or prostrate, Hodgkin's disease, and non-Hodgkin'slymphoma.

Inflammatory diseases include, by way of example, inflammatory jointdisorders, arthritis, and inflammatory-induced cell damage to eye,brain, and other organs. Viral diseases include, by way of example,viral infections, such as hepatitis, retroviral infections, and viralencephalitis. Other disorders include macular degeneration, cataracts,pancreatitis, Crohn's disease, ulcerative colitis, and acceleratedaging.

In another aspect of the present invention, the warm-blooded animal issuffering from an insult selected from the group consisting of physicaltrauma, anoxia, hyperthermia, chemically-induced damage, andradiation-induced damage.

In still yet another aspect of the present invention, the warm-bloodedanimal has been subjected to a procedure selected from the groupconsisting of bypass surgery, chemotherapy, and organ transplantation.

These and other aspects of the present invention will become evidentupon reference to the following detailed description and attacheddrawings. In addition, various references are set forth below whichdescribe in more detail certain procedures or compositions (e.g.,plasmids, etc.), and are therefore incorporated by reference in theirentirety as if each were explicitly incorporated herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bar graph which depicts left ventricular developed pressure,i.e., the difference between peak systolic pressure and resting leftventricular pressure, in the isolated rat heart that was exposed to 45minutes of ischemia by subjecting the heart to an 80% reduction inperfusion flow rate, under anoxic conditions (85% N₂ and 5% CO₂),followed by reperfusion at 15 ml/min. and reoxygenation. There is a morerapid recovery in the hearts that received the peptide (20 mer) (SEQ.ID. No. 6) prior to reperfusion.

FIG. 2 is a bar graph which depicts survival of spinal cord cellsexposed to ammonium persulfate, 1 mM for 2 hours (left) and for 1 hour(right). Cells pretreated with the 20 mer (SEQ. ID. No. 6) had muchbetter survival, i.e., less death. Indeed, the 20 mer almost completelyprevented cell death, compared to the number of dead cells observed inthe absence of ammonium persulfate.

FIG. 3 is an amino acid sequence of one representative streptokinase asdescribed in K. W. Jackson and J. Tang, Biochemistry 21:6620-6625, 1982.A=alanine; C=cysteine; D=aspartic acid; E=glutamic acid;F=phenylalanine; G=glycine; H=histidine; I=isoleucine; K=lysine;L=leucine; M=methionine; N=asparagine; P=proline; Q=glutarnine;R=arginine; S=serine; T=threonine; V=valine; W=tryptophan; Y=tyrosine.

DETAILED DESCRIPTION OF THE INVENTION

As noted above, the present invention generally relates to novelcompositions and the use thereof in methods of ameliorating cell death.Specifically, the present invention pertains to novel peptides derivedfrom a streptokinase and a method of use thereof to ameliorate apoptosisor necrosis.

Within the context of the present invention, the term “cell death”refers to apoptosis or necrosis. The term “apoptosis” refers toprogrammed cell death. The term “necrosis” refers to cell death as aresponse to overwhelming cellular or tissue injury. The term“ameliorate” or “amelioration” refers to an inhibition of cell deathsuch that the incidence of cell death is generally decreased by 50%-80%,typically decreased by greater than 80% and, preferably, decreased bygreater than 95%.

Peptides and Peptide Analogues

As noted above, the peptides of the present invention can be obtained orderived from a streptokinase (e.g., available from ICN, Inc., CostaMesa, Calif., No. 101114) (FIG. 3) and identified by their ability toameliorate cell death. In the context of the present invention, the term“streptokinase” includes any analogues, homologues, mutants, isomers, orderivatives, in addition to the naturally occurring molecule. The term“derived” refers to construction of a peptide based on the knowledge ofa representative streptokinase sequence using any one of severalsuitable means, including, by way of example, isolation or synthesis.

Peptides of the present invention may be synthesized using any one ofseveral means, including tea-bag methodology or solid phase peptidesynthesis procedures described by Merrifield et al. (Biochemistry21:5020-31, 1982), Houghten Wellings, D. A. (Proc. Nat'l. Acad. Sci.(USA) 82:5131-35, 1985); Atherton, E., Methods in Enzymology 289:44-66,1997, or Guy, C. A.; Fields, G. B., Methods in Enzymology 289:67-83,1997, or using a commercially available automated synthesizer, such asthe Applied Biosystems 430 A Peptide Synthesizer.

Alternatively, suitable peptides may be isolated from streptokinase bydigestion of the molecule using any suitable means including, by way ofexample, a protease including plasminogen, trypsin, urokinase,enterokinase, pepsin, papain, and staphylococcus aureus protease(“SAP”), or any combination thereof. Preferably, streptokinase isdigested with plasminogen.

Suitable peptides prepared by either of the means described above may bepurified using any one of several suitable means, including affinitycolumns, salt precipitations, anion/cation exchange columns, sizingcolumns, and gel electrophoresis based on size and charge. Preferably,purification is accomplished using reverse-phase high pressure liquidchromatography (HPLC).

Suitable peptides, prepared as described above, may be assayed using anyone of several suitable means of identifying their ability to amelioratecell death, including culturing three separate biological preparations:(1) and (2) are cultured for a period of time and under suitableconditions to induce apoptosis; and (3) is cultured as a control group.Apoptosis can be induced by any one of several means, includingchemotherapeutic agents, hypoosmotic shock, ultraviolet radiation,gamma-radiation, soft beta-radiation, serum deprivation, or, specificreceptor mediated or non-receptor mediated agents. Preferably, apoptosisis induced using ammonium persulfate which induces oxidative damage and,ultimately, results in cell death.

The peptide to be screened is administered to either biologicalpreparation (1) or (2), and the percent cell death ascertained in allthree biological preparations using, for example, trypan blue exclusion.The success of the peptide, for example, if added to biologicalpreparation (1), can be gauged by comparison with the cell death inbiological preparations (2) and (3). Generally, a 50%-80% decrease incell death and, preferably, a greater than 80% decrease, over biologicalpreparation (2), is the indicia of a successful peptide. Even morepreferably, a greater than 95% decrease in cell death is the indicia ofa successful peptide. Alternatively, a method such as that disclosed inWO 94/25621, may be suitable for screening the compounds of the presentinvention.

Suitable peptides may be analyzed by any one of several means toascertain their composition, including, by way of example, amino acidanalysis (e.g., R. L. Heinriksen and S. C. Meredith, Anal. Biochem.160:65-74, 1984) after gas phase hydrolysis (N. M. Meltzer et al., Anal.Biochem. 160:356-61, 1987). The sequence of the streptokinase peptidemay be confirmed by Edman degradation on a commercially availablesequencer (e.g., R. M. Hewick et al., J. Biol. Chem. 15:7990-8005,1981). Mass Spectral techniques can also be utilized for sequencingpeptides and peptide libraries (see e.g., Brünjes, J.; Metzger, J. W.;Jung, G. in “Combinatorial Peptide and Nonpeptide Libraries”, G. JungEd., VCH publishing, New York 1996, chapter 18, pp 511-521).

In a preferred embodiment of the present invention, suitable peptidesmay have the following core amino acid sequences: VAL-ASP-VAL(including—SER/TYR-VAL-ASP-VAL- (SEQ. ID. No. 13); -VAL-ASP-VAL-GLU/ASP-(SEQ. ID. No. 14); -SER/TYR-VAL-ASP-VAL-GLU/ASP- (SEQ. ID. No. 15); and-VAL-ASP-VAL-GLU/ASP-TYR/THR- (SEQ. ID. No. 16)).

Particularly preferred peptides in this regard include the followingamino acid sequences:

a. SER-VAL-ASP-VAL-GLU-TYR (SEQ. ID. No. 1)

b. TYR-VAL-ASP-VAL-ASP-THR (SEQ. ID. No. 2)

c. THR-VAL-ASP-VAL-GLU-TYR (SEQ. ID. No. 3)

d. TYR-VAL-ASP-VAL-ASP-THR-ASN-GLU-LEU-LEU-LYS (SEQ. ID. No. 4)

e.SER-VAL-ASP-VAL-GLU-TYR-THR-VAL-GLN-PHE-THR-PRO-LEU-ASN-PRO-ASP-ASP-ASP(SEQ. ID. No. 5)

f.SER-VAL-ASP-VAL-GLU-TYR-THR-GLN-PHE-THR-ASP-PHE-ARG-GLY-LYS-LEU-THR-LYS-LEU-LEU(SEQ. ID. No. 6)

g.SER-VAL-ASP-VAL-GLU-TYR-THR-VAL-GLN-PHE-THR-PRO-LEU-ASN-PRO-ASP-ASP-ASP-PHE-ARG-PRO(SEQ. ID. No. 7)

h.TYR-VAL-ASP-VAL-ASP-THR-ASN-GLU-LEU-LEU-LYS-SER-GLU-GLN-LEU-LEU-THR-ALA-SER-GLU(SEQ. ID. No. 8)

In the context of the present invention, the term “peptide” includesanalogues and fragments thereof. The term “analogue” refers to anyderivative of the peptide and peptides in which one or more amino acidshave been replaced with amino acids of similar size and charge, e.g.,interchanging LEU and ILE or the attachment of another structure such asa cyclic compound or other molecule to the “peptide.” Analogues alsoinclude peptides which contain one or more amino acids in an alteredconfiguration (i.e., R or S; or, L or D). The term “fragment” refers toany fragment of the peptide which is capable of ameliorating cell deathas described above. Preferably, fragments are at least four amino acidsin length; even more preferably, fragments are at least six amino acidsin length (see eg., SEQ I.D. Nos. 13, 14, 15 and 16).

Peptides of the present invention may also be modified in order toimprove potency, bioavailability, and/or efficacy. For example, withinone embodiment of the invention D-amino acid peptides, or retroenantiopeptide sequences may be generated in order to improve the bioactivityand chemical stability of a peptide structure (see, e.g., Juvvadi etal., J. Am. Chem. Soc. 118, 8989-8997, 1996; Freidinger et al., Science,210, 656, 1980).

Lactam constraints (see Freidinger, supra), and/or azabicycloalkaneamino acids as dipeptide surrogates can also be utilized to improve thebiological and pharmacological properties of the native peptides (see,e.g., Hanessian et al., “Design and Synthesis of ConformationallyConstrained Amino Acids as Versatile Scaffolds and Peptide Mimetics,”Tetrahedron 53:12789-12854, 1997).

Amide bond surrogates, such as thioamides (see Artis, D. R.; Lipton, M.A., J. Am. Chem. Soc. 120:12200, 1998), secondary and tertiary amines,heterocycles see, for example, (a) Zabrocki, J.; Dunbar, J. B.;Marshall, K. W.; Toth, M. V.; Marshall, G. R., J. Org. Chem. 57:202,1992; (b) Garofolo, A.; Tarnus, C.; Remy, J.-M.; Leppik, R.; Piriou, F.;Harris, B.; Pelton, J. T. In Peptides: Chemistry, Structure and Biology,J. E. Rivier and G. R. Marshall, Editors; ESCOM Science Publishers B.V.: Leiden, The Netherlands, 833-834, 1990; (c) Beusen, D. D.; Zabrocki,J.; Slomczynska, U.; Head, R. D.; Kao, J. L.-F.; Marshall, G. R.,Biopolymers 36:181, 1995; (d) Abell, A. D.; Hoult, D. A.; Jamieson, E.J., Tetrahedron Lett. 33:5831, 1992), olefin (see for example: Andres,C. J.; Macdonald, T. L.; Ocain, T. D.; Longhi, D. J. Org. Chem. 58:6609,1993) and floroolefin replacements (see for example: (a) Boros, L. G.;De Corte, B.; Gimi, R. H.; Welch, J. T.; Wu, Y.; Handschumacher, R. E.,Tetrahedron Lett. 35:6033, 1994; (b) Welch, J. T.; L in, J. Tetrahedron52:291, 1996), among others (see review in Spatola, A. F. in “Chemistryand Biochemistry of Amino Acids, Peptides and Proteins” Wenstein, B. Ed.Marcel Dekker, New York, 1983 Vol. 7, pp 267-357) can also be utilizedto prevent enzymatic degradation of the peptide backbone (therebyresulting in improved activity).

Replacement of the aromatic amino acids such as Phe and Tyr byconstrained aromatic amino acid analogs can also be utilized to restrictthe geometry of the aromatic ring and thereby improve receptor affinity.Examples of syntheses of the constrained aromatic amino acid analogs aswell as lead references for their use in studying peptide structures canbe found in: (a) Gibson (née Thomas), S. E.; Guillo, N.; Middleton, R.J.; Thuilliez, A.; Tozer, M. J. J. Chem. Soc., Perkin Trans. 1:447,1997; (b) Collot, V.; Schmitt, M.; Marwah, A. K.; Norberg, B.;Bourguignon, J.-J. Tetrahedron Lett. 38:8033, 1997; (c) Kazmierski, W.M.; Urbanczyk-Lipkowska, Z.; Hruby, V. J. J. Org. Chem. 59:1789, 1994;(d) Cativiela, C.; Diaz-de-Villegas, M. D.; Avenoza, A.; Peregrina, J.M. Tetrahedron 49:10987, 1993; (e) de Laszlo, S. E.; Bush, B. L.; Doyle,J. J.; Greenlee, W. J.; Hangauer, D. G.; Halgren, T. A.; Lynch, R. J.;Schorn, T. W.; Siegl, P. K. S. J. Med. Chem. 35:833, 1992; (f) Seebach,D.; Boes, M.; Naef, R.; Schweizer, W. B. J. Am. Chem. Soc. 105:5390,1983; (g) Chung, J. Y. L.; Wasicak, J. T.; Arnold, W. A.; May, C. S.;Nadzan, A. M.; Holladay, M. W. J. Org. Chem. 55:270, 1990; (h) Herdeis,C.; Hubmann, H. P.; Lotter, H. Tetrahedron: Asym. 5:351, 1994; (i)Belokon', Y. N.; Bulychev, A. G.; Pavlov, V. A.; Fedorova, E. B.;Tsyryapkin, V. A.; Bakhmutov, V. A.; Belikov, V. M. J. Chem. Soc.,Perkin Trans. 1:2075, 1988; (3) Sarges, R.; Tretter, J. R., J. Org.Chem. 39:1710, 1974; (k) Semple, J. E.; Minami, N. K.; Tamura, S. Y.;Brunck, T. K.; Nutt, R. F.; Ripka, W. C., Bioorg. Med. Chem. Lett.7:2421, 1997; (1) Pastó, M.; Moyano, A.; Pericàs, M. A.; Riera, A., J.Org. Chem. 62: 8425, 1997; (m) Kühn, C.; Lindeberg, G.; Gogoll, A.;Hallberg, A.; Schmidt, B. Tetrahedron 53:12497, 1997; (n) Liao, S.;Shenderovich, M. D.; Lin, J.; Hruby, V. J., Tetrahedron 53:16645, 1997;(o) Van Betsbrugge, J.; Van Den Nest, W.; Verheyden, P.; Tourwé, D.,Tetrahedron 54:1753, 1998.

Conversion of linear peptides to cyclic peptide analogs can also beutilized to improve metabolic stability, since cyclic peptides are muchless sensitive to enzymatic degradation (see generally, Veber, et al.Nature 292:55-58, 1981).

Yet other peptide analogues may be generated based upon the presence ofmany valine residues in some of the peptide sequences described herein.Within one embodiment, peptide sequences possessing constrained valineanalogs such as a proline-valine chimera (see generally Sharma andLubell, “Regioselective Enolization and Alkylation of4-Oxo-N-(9-phenylfluoren-9-yl)proline: Synthesis of EnantiopureProline-Valine and Hydroxyproline-Valine Chimeras,” J. Org. Chem.61:202-209, 1996), can be generated.

Similarly, amino acid chimeras that contain proline analogues possessingthe characteristics of other amino acids can be generated for studyingthe spatial requirements for receptor affmity and biological activity ofpeptides. Such analogs would be particularly useful for modifing the Aspand Glu residues of the active peptides.

Furthermore, α-alkyl branched amino acids (see: Toniolo, C.; Benedetti,E., Macromolecules 24:4004, 1991; and references therein.), dehydroamino acids (see for example: Dehydro-Enkephalins IV. DiscriminativeRecognition of Delta and Mu Opiate Receptors by Enkephalin Analogs. Y.Shimohigashi, C. H. Stammer, T. Costa et al., Biochem. Biophys. Res.Commun. 104:583-590, 1982) as well as cyclopropane amino acid analogs(reviewed in: C. H. Stammer Tetrahedron 46:2231-2254, 1990) can beintroduced into peptides in order to induce local conformationalconstraint that can enhance activity by restricting the back-bone andside-chain geometry of the native peptide.

Peptides can also be modified in order to improve absorption (seegenerally, Annual Reviews of Medicinal Chemistry), including forexample, addition of sugar residues to enhance transport across theblood-brain barrier.

Peptides can also be modified utilizing end group capping as esters andamides in order to slow or prevent metabolism and enhance lipophilicity.Dimers of the peptide attached by various linkers may also enhanceactivity and specificity (see for example: Y. Shimohigashi et al.,“Enkephalin Dimers and Their Handicapped Analogs as Probes forElucidation of Ligand-Opiate Receptor Interaction,” in Peptide Chemistry1988, Proceedings of the 26th Symposium on Peptide Chemistry, Tokyo,October 24-26, pgs. 47-50, 1989).

Other peptide modifications suitable for use within the presentinvention include the addition to either or both ends of each peptide,or to the VAV sequence, D-penicillamine, or —NH₂, cyclization of thepeptide, linkage of two or more peptides via a bridge (e.g., utilizinghydrazide), halogenation of peptide sequences, addition of Phe residues,and conjugation with other moieties, such as a methyldihydropyridine.

Peptide analogues can also be generated and selected from combinatoriallibraries. Representative examples of suitable techniques are describedin more detail in U.S. Pat. Nos. 4,528,266 and 4,359,535, and PatentCooperation Treaty Publication Nos. WO 92/15679, WO 92/15677, WO90/07862, WO 90/02809, or purchased from commercially available sources(e.g., New England Biolabs Ph.D.™ Phage Display Peptide Library Kit).

Expression of Peptides

Another aspect of the present invention provides polynucleotides whichencode the above described peptides, analogues or fragments thereof.Polynucleotides and analogues thereof include, by way of example, RNA,DNA analogues thereof, including chimerics and PNA. The polynucleotidesof the present invention may be synthesized or isolated. Synthesis maybe accomplished using any one of several means including standardpolynucleotide synthesis procedures. The polynucleotides coding for theaforementioned peptides could either be inserted into a standard plasmidor viral vector, introduced into bacterial or eukaryotic cells and thepeptides of the present invention expressed and isolated.

Expression of the inserted polynucleotide can be determined in vitrousing any one of the techniques described above. Expression of theinserted polynucleotide can be determined in vivo using any one ofseveral methods, including, by way of example, immunofluorescence usinga fluoresceinated ligand.

The sequences, constructs, vectors and other materials comprising thepresent invention can advantageously be in the enriched or isolatedform. Within the context of the present invention, “enriched” means thatthe concentration of the material is at least about 2, 3, 4, 10, 100, or1000 times its natural concentration, for example, advantageously 0.01%by weight, preferably at least about 0.1% by weight. Enrichedpreparations of about 0.5%, 1%, 5%, 10%, and 20%, by weight, are alsocontemplated.

Within the context of the present invention, the term “isolated”requires that the material be removed from its original environment(e.g., the natural environment if it is naturally occurring). Forexample, a naturally occurring oligonucleotide or peptide present in aliving animal is not “isolated,” but the same oligonucleotide orpeptide, separated from some or all of the coexisting materials in thenatural system, is “isolated.” Within one embodiment, when the term“purified” is utilized in the context of peptides, this means that, uponapplication of the peptide to SDS-PAGE analysis, followed by Coomassieblue staining, a single band is visible on the gel.

Another aspect of the present invention provides constructs includingone or more of the polynucleotides, as broadly described above. Theconstructs comprise a vector, such as a plasmid or viral expressionvector, into which a polynucleotide of the present invention has beeninserted, in either a sense or antisense orientation. Preferably, theconstruct further contains regulatory regions, including, for example, apromoter, operably linked to the polynucleotide. Large numbers ofsuitable vectors and promoters are known and are commercially available.The following expression vectors are provided by way of example:Prokarvotic: pBC, pBluescript SK, pBK, pNH8a, pNH16a, pNH18a, pNH46a,pCR-SCRIPT (Stratagene), ptrc99A, pKK223-3, pKK233-3, pDR540, pRIT5(Pharmacia). Eukarvotic: TBK, pSV2cat, pOG44, pOG45, pXT1, pMC1neo,pMC1neo Poly A, pSG, pSG5 (Stratagene), pSVK3, pBPV, pMSG, pSVL(Pharmacia). Viral: retroviral, adenoviral, phage-based vectors, andvaccinia virus.

Promoter regions may be selected from any desired gene usingchloramphenicol transferase (“CAT”) vectors or other vectors withselectable markers. Two appropriate vectors are pKK232-8 and pCM7.Particular named bacterial promoters include lacI, lacZ, T3, T7, gpt,lambda P_(RO) and trc. Eukaryotic promoters include CMV immediate early,HSV thymidine kinase, early and late SV40, LTRs from retrovirus andmouse metallothionein-I. Selection of the appropriate vector andpromoter is well within the level of one of ordinary skill in the art.

In a further embodiment, the present invention provides host cellscontaining the above-described construct. The host cell can be aeukaryotic cell, for example, a mammalian cell or a yeast cell; or aprokaryotic cell, such as a bacterial cell. Introduction of theconstruct into the host cell can be affected using any one of severalmethods known in the art, including by calcium phosphate transfection,DEAE, dextran mediated transfection, infection, or electroporation, asdescribed in detail in, e.g., Davis et al., Basic Methods of MolecularBiology, 1986.

Constructs in host cells can be used in a conventional manner to producethe peptides coded by the polynucleotides, as described above, or thehost cells can be administered directly to an animal in need thereof, asdescribed below. Alternatively, the encoded peptide can be syntheticallyproduced by conventional peptide synthesizers.

Gene Therapy

A wide variety of gene delivery vectors may be utilized to deliverand/or express a desired peptide of interest in host cells. For example,within one aspect of the present invention, retroviral gene deliveryvehicles may be utilized. Briefly, retroviral gene delivery vehicles ofthe present invention may be readily constructed from a wide variety ofretroviruses, including for example, B, C, and D type retroviruses aswell as spumaviruses and lentiviruses (see RNA Tumor Viruses, SecondEdition, Cold Spring Harbor Laboratory, 1985). Such retroviruses may bereadily obtained from depositories or collections such as the AmericanType Culture Collection (“ATCC”; Rockville, Md.), or isolated from knownsources using commonly available techniques. Representative examples ofretroviral gene delivery vectors are described in more detail in EP0,415,731; PCT Publication Nos. WO 90/07936; WO 91/0285, WO 9311230; WO9310218, WO 9403622; WO 9325698; WO 9325234; and U.S. Pat. Nos.5,219,740, 5,716,613, 5,851,529, 5,591,624, 5,716,826, 5,716,832, and5,817,491.

Other suitable gene delivery vectors can be generated from alphaviruses(see e.g., U.S. Pat. Nos. 5,091,309 and 5,217,879, 5,843,723, and5,789,245), recombinant adenoviral vectors (see e.g., U.S. Pat. No.5,872,005), and numerous other viruses such as pox viruses, such ascanary pox virus or vaccinia virus (Fisher-Hoch et al., PNAS 86:317-321,1989; Flexner et al., Ann. N.Y. Acad. Sci. 569:86-103, 1989; Flexner etal., Vaccine 8:17-21, 1990; U.S. Pat. Nos. 4,603,112, 4,769,330 and5,017,487; WO 89/01973); SV40 (Mulligan et al., Nature 277:108-114,1979); influenza virus (Luytjes et al., Cell 59:1107-1113, 1989;McMicheal et al., N. Eng. J. Med. 309:13-17, 1983; and Yap et al.,Nature 273:238-239, 1978); herpes (Kit, Adv. Exp. Med. Biol.215:219-236, 1989; U.S. Pat. No. 5,288,641); HIV (Poznansky, J. Virol.65:532-536, 1991); measles (EP 0 440,219); Semliki Forest Virus, andcoronavirus, as well as other viral systems (e.g., EP 0,440,219; WO92/06693; U.S. Pat. No. 5,166,057).

In addition to the above viral-based vectors, numerous non-viral genedelivery vehicles may likewise be utilized within the context of thepresent invention. Representative examples of such gene deliveryvehicles include direct delivery of nucleic acid expression vectors ornaked DNA alone (see e.g., U.S. Pat. Nos. 5,814,482 and 5,580,859),polycation condensed DNA linked or unlinked to killed adenovirus (Curielet al., Hum. Gene Ther. 3:147-154, 1992), DNA ligand linked to a ligand(Wu et al., J. of Biol. Chem. 264:16985-16987, 1989), and nucleic acidcontaining liposomes (e.g., WO 95/24929 and WO 95/12387).

Pharmaceutical Compositions, and Methods of Treatment

Pharmaceutical compositions containing the peptide, fragments oranalogues thereof, or associated polynucleotides and constructs thereof(hereinafter referred to as “the compounds of the present inventions”)in an admixture with a pharmaceutical carrier or diluent can be preparedaccording to conventional pharmaceutical compounding techniques.Administration should account for the possibility of degradation ofcompounds of the present invention. The carrier may take a wide varietyof forms depending on the form of preparation desired foradministration, e.g., intravenous, intradermal, intraperitoneal,intramuscular, nasal, oral, topical, aerosol, suppository, parenteral orspinal injection. Preferably, the peptide is administered directly tothe targeted site, i.e., by stereotactic injection or other suitablemeans.

Pharmaceutical composition containing the peptide, fragment or analoguesthereof or polynucleotides and constructs thereof may be combined withagent or drug that inhibits or delays or retards themetabolism/degradation of the peptide, fragments or analogues.

If necessary, the pharmaceutical preparations can be subjected toconventional pharmaceutical adjuvants such as preserving agents,stabilizing agents, wetting agents, salts for varying the osmoticpressure, and the like. The present pharmaceutical preparations may alsocontain other therapeutically valuable substances.

Within this embodiment of the present invention, the compounds of thepresent invention may be delivered using a suitable liposome deliverysystem, including, by way of example, those described in U.S. Pat. No.4,241,046; 4,235,871; 4,394,448; 4,483,929; 4,745,074; 4,766,046;4,873,088; 5,077,057; 5,180,713; and 5,277,914; or in Rahman et al., J.of Liposome Research 4:167-192, 1994.

Compounds of the present invention may also be delivered by chronicinfusion using any suitable method known in the art, including anosmotic minipump (Alza Corp.) or delivery through a time release orsustained release medium. Suitable time release or sustained releasesystems include any methods known in the art, including media such asElvax (or see, for example, U.S. Pat. Nos. 5,015,479, 4,088,798,4,178,361, and 4,145,408). When using chronic infusion, time release, orsustained release mechanisms, the composition may be stereotacticallyinjected, orally, parenterally, or intramuscularly administered.

When polynucleotides of the present invention or constructs thereof aretransfected or infected into a mammalian host cell, the mammalian cellsmay be administered to the patient in need thereof by any method knownin the art, including that outlined in U.S. Pat. No. 5,082,670 (see alsothe gene therapy discussion provided above).

In another aspect of the present invention, the compositions of thepresent invention are utilized to treat diseases and conditions relatedto aging, cellular differentiation, and physical insult. Theseconditions and diseases include, by way of example, infectious diseases(e.g., viral, bacteria, parasite, or, prion-based diseases),degenerative disorders, immune disorders, aging, cardiovasculardisorders, and neoplastic disorders.

In one embodiment of this aspect of the present invention, compositionsof the present invention (as described above) are administered to treator prevent a warm-blooded animal suffering from or susceptible to aviral disease. The association of cell death with a particular viraldisorder may be determined by standard means. Such viral diseasesinclude, by way of example, hepatitis, retroviral infections, and viralencephalitis, and AIDS/HIV (Fauci, A. S., Science 262:1011, 1993;Ameisen, J. C., Immunol. Today 13:388, 1992; Gorla, R. et al., AIDSResearch and Human Retroviruses 10(9):1097).

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from, or susceptible to, aneurodegenerative disorder. The association of cell death with aparticular neurodegenerative disorder may be determined by establishing,for example, indicators of defects of neurologic function. Suchneurodegenerative disorders include, by way of example, Parkinson'sdisease, (Beal, M. F. et al., TINS 16(4):125, 1993; Bloem, B. R. et al.,J. Neurol. Sci. 97:293 1990; Brennan, W. A. et al., J. Neurochem.44:1948, 1985); Alzheimer's disease, (Beal, M. F. et al., TINS16(4):125, 1993, Beal, M. F., Ann. Neurol. 31:119, 1992); Huntington'sdisease, (Beal, M. F. et al. TINS 16(4):125, 1993; Bloem, B. R. et al.,J. Neurol. Sci. 97:293 1990; Brennan, W. A. et al., J. Neurochem.44:1948, 1985); cerebellar degenerations, (Beal, M. F. et al., TINS16(4):125, 1993); and, familial amyotrophic lateral sclerosis (FALS)(Olanow, C. W., TINS 16:439, 1993).

Compounds of the present invention may also be administered to treat orprevent a warm-blooded animal suffering from, or susceptible to, acardiovascular disease. The association of cell death with a particularcardiovascular disease may be determined by any suitable means includingmicroscopy of trypan blue exclusion, histologic examination fornecrosis, or, DNA fragmentation assays (see Fliss and Gattinger, 1996,infra). Such cardiovascular diseases include, by way of example,atherosclerosis, myocardial infarction, heart failure, cardiomyopathy,myocardial reperfusion injury, and hypertensive heart disease.Assessment of the suitability of peptides, or peptide analogues in thetreatment of coronary disease may be accomplished, for example,utilizing the rat model of ligation/reperfiusion (see generally, Flissand Gattinger, Cir. Res. 79:949-956, 1996).

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from, or susceptible to, autoimmunedisease. The association of cell death with a particular autoimmunedisorder may be determined, for example, by biochemical tests such asantibodies to virus or anti-DNA antibodies, microscopic appearance ofblood cells and histologic appearance of affected tissue. Such immunediseases include, by way of example, AIDS/HIV, autoimmune disease andimmune deficiencies. Autoimmune diseases include rheumatoid arthritis,systemic lupus erythematosus, insulin-dependent diabetes mellitus,lupus, pernicious anemia, dermatomyositis, enythema nodosum, Sjögren'ssyndrome, temporal arteritis, myasthenia gravis, Wegener'sgranulomatosis, glomerulonepliritis, anti-phospholipid syndrome, andautoimmune polyarthritides. The connection between apoptosis andautoimmune disease has been documented in WO 94/08454.

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from, or susceptible to, a neoplasticdisorder. The association of cell death with a particular neoplasticdisorder may be determined by, for example, microscopic examination ofblood elements, histologic appearance of tissue, and genetic testing oftissue and blood-formed elements. Such neoplastic disorders include, byway of example, leukemia, sarcomas, myelomas, carcinomas, neuromas,melanoma, cancers of the breast, brain, colon, cervix, and prostrate,Hodgkin's disease, and non-Hodgkin's lymphoma.

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from, or susceptible to, an inflammatorydisorder. The association of cell death with a particular inflammatorydisorder may be determined by, for example, x-ray examination, bloodtests such as, but not restricted to, rheumatoid factor and histologicappearance of tissue. Such inflammatory disorders include, by way ofexample, inflammatory joint disorders such as arthritis and inflammatoryinduced cell damage to the eye, brain, and other organs.

Compounds of the present invention may also be administered to treat awarm-blooded animal which has been subjected to physical insult. Theterm “physical insult” refers to injury resulting from sudden or severeshock, for example, from physical trauma, anoxia, hyperthermnia,hypothermia, chemically induced damage, and acute tissue injury such astrauma to the brain, spinal cord, kidney, heart, lungs, liver, skin andany other organ of the body.

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from such conditions as ischemia orreperfiusion injury of various body organs, including, but not limitedto, myocardial ischemia and reperfusion injury, renal ischemia, brainischemia and/or reperfusion injury, spinal cord ischemia or reperfusioninjury, retinal ischemia or infaction, and stroke.

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from such toxic insult as liver toxicity,pulmonary toxicity, and toxic damage to other body organs fromchemicals, radiation and other noxious substances.

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from such conditions as maculardegeneration, cataract formation, pancreatitis, CrohI's disease,ulcerative colitis and accelerated aging.

Compounds of the present invention may also be administered to treat awarm-blooded animal suffering from spinal cord disease, such as motorneuron diseases, degeneration of spinal cord, Guillan Bare Syndrome, anddemyelinating disease.

Compounds of the present invention may also be administered to treat awarm-blooded animal which has been subjected to a procedure with whichcell death is associated. Such procedures include, by way of example,cardiac catherization, bypass surgery, chemotherapy, andchemically-induced reperfusion. This association is determined byclinical examination and appropriate testing, depending on the organ. Byway of example, such tests include, echocardiograms, electrocardiograms,nuclear studies, and biochemical tests, e.g., CK, and CK-MB.

Compounds of the present invention may also be administered to treat awarm-blooded animal which has been administered therapeutics whichsubject the animal to oxidative stress. The free radical productionassociated with oxidative stress may be identified and evaluated toascertain the effect of the therapeutics using any suitable method,including thiobarbaturic acid, colormetric assays (TBARS), and spinresonance. Such therapeutics include, by way of example, clozapine, AZT,and anthracyclines.

Compounds of the present invention may also be administered to abiological preparation. In the context of the present invention, theterm “biological preparation” refers to an ex vivo cell culture.

The compounds of the present invention or any combination thereof areadministered in a therapeutically effective amount. A therapeuticallyeffective amount is that amount sufficient to reduce cell death. Atherapeutically effective amount can be determined by in vitroexperiment followed by in vivo studies. The optimal dosage is that whichproduces maximal improvement with tolerated side effects. The optimaldosage is determined empirically and balances the benefits and adverseside effects.

The term “treatment” as used within the context of the presentinvention, refers to reducing or alleviating symptoms in a subject,preventing symptoms from worsening or progressing, inhibition orelimination of the causative agent, or prevention of the infection ordisorder in a subject who is free therefrom. Thus, for example,treatment of infection includes destruction of the infecting agent,inhibition of or interference with its growth or maturation,neutralization of its pathological effects and the like. An unbalancedstate disorder is “treated” by partially or wholly remedying theimbalance which causes the disorder or which makes it more severe.Representative examples of warm-blooded animals that may be “treated”include humans, horses, cows, pigs, sheep, dogs, cats, rats and mice.

A disorder is “treated” by partially or wholly remedying the deficiencywhich causes the disorder or which makes it more severe. For example, adisorder such as myocardial infarction is considered to be treated ifadministration of the composition provided herein (i) improves survival,(ii) results in fewer morbid events from the complications of myocardialinfarction (e.g., heart failure and arrhythmias), or (iii) there isevidence of a lesser amount of damage to the heart due to a myocardialinfarction (e.g., as assessed by the release of creatine kinase orimaging of the heart).

The following examples are provided by way of illustration, and not byway of limitation.

EXAMPLES Example 1 Amelioration of Cell Death in Cardiac Myocytes

This example serves to demonstrate an assay useful to test peptides fortheir ability to ameliorate cell death.

Cardiac myocytes from embryonic chick hearts were grown in culture usingthe procedures described in Rabkin, Exper. Cell. Res. 188:262-266, 1990.Briefly, white Leghorn eggs were incubated in an automatic incubator(March Rollex, Calif., USA) for 7 days at 37.8° C. and 87% humidity.Hearts were then isolated under sterile conditions from the 7-day chickembryo. Blood and connective tissue were removed under a dissectingmicroscope in a solution of balanced salts (DMS8) with the followingcomposition (mM): NaCl 116, KCl 5.4, NaH₂PO₄ 1 and dextrose 5.6.Disaggregation was carried out by 5-minute digestions in 0.005% trypsin(Gibco Laboratories, Burlington, Ontario), 0.1% BSA and 1×10⁷ DNAse permL, DMS8 (Worthington Biochemicals, Frederic, N.J., USA) at 37° C. Afterthree digestions, the digests were diluted 1:5 in culture medium and thecells centrifuged for three minutes at 1000 g and plated.

The cultured cardiac myocytes were incubated with 1 mM ammoniumpersulfate for 2 hours at 37° C. to induce oxidative damage. Cellviability was assessed by Trypan blue exclusion. Six samples containingcells were then incubated with 0.0, 0.000375, 0.00375, 0.0375, 0.375 and37.5 μM streptokinase (Hoechts-Roussel Pharmaceuticals), respectively,and 0.0, 0.000246, 0.00246, 0.0246, 0.246 and 24.6 μM plasminogen,respectively (see Table 1), for 1-2 hours at 37° C. and assessed byTrypan blue exclusion.

Control cell samples were treated with 1 mM ammonium persulfate in theabsence of streptokinase (STK) and plasminogen under the sameconditions.

The results are described in Table 1 in terms of the percent cell deathinduced by ammonium persulfate. The data represents the mean of six (6)duplicate determinations, none of which differed by more than 5%.

TABLE 1 Streptokinase Plasminogen Cell Death (μM) (μM) (%) 0 (Control) 0(Control) 81 0.000375 0.000246 50 0.00375  0.00246  37 0.0375  0.0246 29 0.375   0.246   25 37.5    24.6    16

Example 2 Separation of Streptokinase Fragments by Reverse Phase HPLC

This example serves to demonstrate the isolation of peptides derivedfrom streptokinase and their ability to ameliorate cell death in cardiacmyocytes.

Streptokinase was incubated with plasminogen at a 1:1 molarconcentration for 1-2 hours at 37° C. Streptokinase and plasminogenfragments were subsequently separated using a reverse phase phenyl HPLCcolumn (Waters) and a linear gradient of 1%/min and an isopropanolgradient in 0.1 ammonium bicarbonate buffer, pH 6.5.

Each of the nineteen (19) resulting fractions was tested for thepeptide's ability to ameliorate cell death according to the assaydescribed in Example 1. The results of this assay are presented in Table2. The data in Table 2 represent the mean of duplicate determinations.None of the determinations differed by more than 5%.

TABLE 2 Fraction Number Cell Death (%)  1 87  2 79  3 79  4 62  5 83  677  7 81  8 79  9 82 10 63 11 78 12 29 13 39 14 80 15 76 16 63 17 79 1874 19 77

The HPLC-purified peptides eluted in fractions 12 and 13 were analyzedby amino acid analysis (R. L. Heinriksen and S. C. Meredith, Anal.Biochem. 160:65-74, 1984) after gas phase sequencing (N. M. Meltzer etal., Anal. Biochem. 160:356-61, 1987). The seqence of the purifiedpeptide was determined by Edman degradation on a commerically availableseequencer (R. M. Hewick et al., J. Biol. Chem. 15:7990-8005, 1981). Thesequences were:

fraction 12: YVDVDTNELLKSEQLLTASE (SEQ. ID NO. 8)

fraction 13: SVDVEYTVQFTPLNPDDDFRP (SEQ. ID NO. 7)

Example 3 Amelioration of Cell Death by Synthesized Peptides

This example serves to demonstrate the suitability of specific peptidesin amelioration of cell death.

Based on the sequences identified in Example 2, peptides weresynthesized using a commercially available automated synthesizer(Applied Biosystems 430 A Peptide Synthesizer), purified by and testedaccording to the assay described in Example 1 for their ability toameliorate cell death in cardiac myocytes. The sequences for thesepeptides were:

6 mer #1: SVDVEY (SEQ. ID NO. 1)

6 mer #2: YVDVDT (SEQ. ID NO. 2)

6 mer #3: TVDVEY (SEQ. ID NO. 3)

11 mer: YVDVDTNELLK (SEQ. ID NO. 4)

18 mer: SVDVEYTVQFTPLNPDDD (SEQ. ID NO. 5)

20 mer: SVDVEYTQFTDFRGKLTKLL (SEQ. ID NO. 6)

fraction 12: YVDVDTNELLKSEQLLTASE (SEQ. ID NO. 8)

fraction 13: SVDVEYTVQFTPLNPDDDFRP (SEQ. ID NO. 7)

Irrelevant #1: NFLRGKLKLYTGEACRTGDR (SEQ. ID NO. 9)

Irrelevant#2: RLILDSRVLERYLLEAKEAE(SEQ.ID. NO. 10)

Irelevant #3: EVTEEEETVPLKThE-AMIDE (SEQ. ID NO. 11)

Table 3 presents the percentage of dead cells as measured by Trypan blueassessment as described in Example 1. The data in Table 3 representsmeans of duplicate determinations, which did not differ by more than 5%.

TABLE 3 Peptide Concentration (μM): Peptide 0 5 10 15 20 20 mer 80.347.6 35.4 31.6 23.1  6 mer #1 82.4 51.9 — — 36.8  6 mer #2 82.4 37.0 — —25.4  6 mer #3 — — — — — 11 mer 80.7 38.6 — — — 18 mer 84.5 — — — 54.4Irrelevant #1 79.6 77.1 — — 67.6 Irrelevant #2 79.6 77.4 — — 76.1Irrelevant #3 79.6 79.5 — — 81.1

These peptides effectively protect cells against cell death in the lowmicromolar range and exhibit a good dose-response relationship. Thehighest concentration of the 20 mer peptide (SEQ. ID NO. 6) was able toreduce the number of dead cells to the 20% range, despite the presenceof agents designed to induce cell death. This is comparable to celldeath observed under control conditions (i.e., in the absence ofammonium persulfate). Three irrelevant peptides of different sequences,but approximately the same length, utilized as negative controls, didnot show any significant effect on cell viability in this assay.

Example 4 Amelioration of Cell Death in Isolated Intact Rat Heart

This example serves to demonstrate the ability of the peptides of thepresent invention to ameliorate cell death in the heart.

Rats weighing between 0.3 and 0.4 kilograms were injected with heparinand then 1 hr. later killed by cervical fracture. Their hearts wereimmediately excised and placed in an oxygenated Krebs-Henseleit solutionof the following composition (in millimole/liter): NaCl, 119.9; KCl,6.0; NaHCO₃, 25.0; MgSO₄, 1.2; CaCl₂, 1.6; KH₂PO₄, 1.2; and glucose,10.0. The aorta was cannulated and the heart was perfused withoxygenated Krebs-Henseleit solution, using the Lanngendorff technique ata constant flow of 15 ml per minute with a diastolic perfusion pressuregreater than 50 mm Hg. The perfusate was previously equilibrated andconstantly aerated with 95% 0₂ and 5% CO₂. The right ventricle wasstimulated with square waves of 1 V for 1 ms every 500 ms (Pulsar 6Istimulator, Frederick Haer & Co., Brunswick, Me.). Following a 30 min.equilibration, the left atrium was incised to permit the insertion intothe left ventricle of a balloon-tipped catheter which was inflated at aresting pressure of 20 mm Hg. Left ventricular pressure was measuredusing a Statham pressure transducer (Gould P230 ID) and recorded on aGould polygraph (Model 2900, Gould, Cleveland, Ohio).

The preparation was allowed to stabilize for 30 min. prior tocommencement of the experimental protocol. After obtaining baselinemeasurements, myocardial ischemia was produced by decreasing theperfusate flow to 2.5 ml per minute (80% of control) and by using ananoxic solution (95% N₂ and 5% CO₂). The period of ischemia and hypoxia(hereinafter referred to as “the ischemic period”) lasted 45 minutes.Perfusion rate and oxygenation were then returned to control levels.Left ventricular pressure measurements were recorded before, during, andfor 120 min. after myocardial ischemia.

One group of isolated rat hearts was pretreated with a 20 mer (SEQ. IDNO. 6). The 20 mer (SEQ. ID NO. 6) was added to the perfusate and heartswere perfused starting 15 minutes before reperfusion and continuing for5-10 minutes after reperfusion. Left ventricular developed pressure wasmeasured and compared to a control group of isolated rat heartsreceiving no pretreatment. Left ventricular developed pressure, an indexof left ventricular performance, is the difference between peak systolicpressure and resting left ventricular pressure. The results of thisexperiment are plotted in FIG. 1. Hearts pretreated with the 20 merpeptide (SEQ. ID NO. 6) experienced a rapid recovery.

Example 5 Amelioration of Cell Death in Spinal Cord Cells

This example serves to demonstrate the effectiveness of the peptides ofthe present invention to ameliorate neuronal cell death. Spinal cordcells isolated from embryonic chicks were grown in culture for 5-7 days.Chick spinal cord cells were cultured as described briefly as follows-Cell cultures were prepared from 7-day chick embryo. Ventral portions ofspinal cord were dissected free of meninges and dorsal root ganglia anddiced into small pieces in Dulbecco's phosphate-buffered saline (PBS).Tissue fragments were incubated in PBS with 0.25% trypsin and 20 ug/mlDNase for 30 min at 36° C. Trypsin was inactivated by the addition ofhorse serum and cells were dissociated by gentle pipetting.

Isolated cells were washed, resuspended in medium and plated ontoplastic coverslips in petri dishes. The medium consisted of Eagle'sminimum essential medium (MEM), 10% fetal bovine serum (FBS), 5 mg/mlD-glucose and 25 μg/ml gentamycin. Cells were grown in an incubator with5% CO₂/95% air at 37° C. and the medium was renewed twice a week. Cellswere used for experiment after 14 days.

Both the experimental and control cultures were treated with 1 mMammonium persulfate for 1 or 2 hours at 37° C. The experimental cultureswere treated with either 10 μg/ml or 20 μg/ml of the 20 mer peptide(SEQ. ID NO. 6) for the same length of time. Results of two experiments,each carried out in duplicate, are shown in FIG. 2. The number of deadcells, assayed by trypan blue, in the experimental groups was comparedto that in the control group. Pretreatment with the 20 mer peptide (SEQ.ID NO. 6) dramatically enhanced cell survival.

Example 6 Amerlioration of Cell Death in Human Hematopoietic Cell Lines

This example serves to demonstrate the use of the compounds of thepresent invention in ameliorating serum-deprivation-induced cell death.

The hematopoietic, growth factor dependent cell lines, M07E and TF-1(Mijajima, CDNAX Research Institute, Palo Alto, Calif.), were starvedfor 30 hours in DMEM containing 1% fetal calf serum (Hyclone, Logan,Utah) in the presence or absence of 20 μg/ml of the 20 mer peptide (SEQ.ID NO. 6). Cell viability was measured by one of two methods, trypanblue exclusion or ³H-thymidine incorporation (Alai et al., J. Biol.Chem. 267:18021-18025, 1992).

Cells in the latter group were washed free of the 20 mer (SEQ. ID NO.6), given saturating concentrations of growth factor (5 ng/ml of humaninterleukin-3) and incubated for an additional 22 hours. After the 22hours, 1 μCi of ³H-thymidine (2 Ci/mmol) was added and, after 2 hours,the cellular contents were harvested onto filtermats. Then ³H-thymidineincorporation was measured using an LKB Betaplate Harvester and liquidscintillation counter. The results of this experiment are presented inTables 4 and 5. Note the increased viability of cells treated with the20 mer peptide (SEQ. ID NO. 6).

TABLE 4 TRYPAN BLUE COUNTS (% VIABILITY) Cell Line Control 20 μg/ml 20mer Peptide M07E 11 ± 1% 20 ± 0.5% TF-1  6 ± 1% 29 ± 1%  

TABLE 5 ³H-THYMIDINE COUNTS (COUNTS PER MINUTE) Cell Line Control 20μg/ml 20 mer Peptide M07E 2,003 ± 468 4,282 ± 212  TF-1 14,728 ± 2,82532,701 ± 5,565

Example 7 Animakl Model of Cornoary Artery Occlusion and Reperfusion

Peptides, peptide analogues and organic-molecule analogues of thepresent invention may be readily tested for their ability to treat,prevent, or other ameliorate apoptosis in vivo, utilizing a standard ratmodel of ligation/reperfusion.

Briefly, male Sprague-Dawley rats (250 to 300 gr) are anesthetized with5% halothane/100% oxygen. The animals are intubated and ventilated with1/5% halothane/100% oxygen using a rodent respirator. An incision ismade in the skin on the left side of the chest, and the pectoral musclesretracted to expose the ribs. An incision is made through the fourthintercostal space, and the ribs spread to expose the heart. A ligatureis placed under the left main coronary artery, which is tied off with aslip-knot. The chest is then briefly compressed to expel intraleuralair. The skin incision is then closed using surgical clips, leaving oneend of the coronary suture protruding from the chest. The animals arethen ventilated with room air, and after 45 minutes of occlusion, thecoronary artery is reperfused by pulling on the exteriorized suture torelease the knot and remove the suture.

At the end of the reperfusion or permanent occlusion, the rats areanesthetized with sodium pentobarbital, and the abdomen opened. Onemilliliter of Evans blue dye (5% in saline) is injected into the venacava to stain the area of the myocardium perfused by patent coronaryarteries, thereby delineating the ischemic region by negative staining.Analysis is undertaken of neutrophil content, DNA fragmentation, and insitu end labeling (see generally, Fliss and Gattinger, Cir. Res.79:949-956, 1996).

Peptides and peptide analogues which are administered either prior to,during, or subsequent to ligation and/or reperfiision, and which alter,in a statistically significant manner, the extent of apoptosis withinthe myocardium, may be utilized to treat a wide variety of coronarydiseases where apoptosis occurs.

From the foregoing, it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

16 1 6 PRT Artificial Sequence Synthetic polypeptide 1 Ser Val Asp ValGlu Tyr 1 5 2 6 PRT Artificial Sequence Synthetic polypeptide 2 Tyr ValAsp Val Asp Thr 1 5 3 6 PRT Artificial Sequence Synthetic polypeptide 3Thr Val Asp Val Glu Tyr 1 5 4 11 PRT Artificial Sequence Syntheticpolypeptide 4 Tyr Val Asp Val Asp Thr Asn Glu Leu Leu Lys 1 5 10 5 16PRT Artificial Sequence Synthetic polypeptide 5 Ser Val Asp Val Glu TyrThr Val Gln Phe Thr Pro Leu Asn Pro Asp 1 5 10 15 6 20 PRT ArtificialSequence Synthetic polypeptide 6 Ser Val Asp Val Glu Tyr Thr Gln Phe ThrAsp Phe Arg Gly Lys Leu 1 5 10 15 Thr Lys Leu Leu 20 7 21 PRT ArtificialSequence Synthetic polypeptide 7 Ser Val Asp Val Glu Tyr Thr Val Gln PheThr Pro Leu Asn Pro Asp 1 5 10 15 Asp Asp Phe Arg Pro 20 8 20 PRTArtificial Sequence Synthetic polypeptide 8 Tyr Val Asp Val Asp Thr AsnGlu Leu Leu Lys Ser Glu Gln Leu Leu 1 5 10 15 Thr Ala Ser Glu 20 9 20PRT Artificial Sequence Synthetic polypeptide 9 Asn Phe Leu Arg Gly LysLeu Lys Leu Tyr Thr Gly Glu Ala Cys Arg 1 5 10 15 Thr Gly Asp Arg 20 1020 PRT Artificial Sequence Synthetic polypeptide 10 Arg Leu Ile Leu AspSer Arg Val Leu Glu Arg Tyr Leu Leu Glu Ala 1 5 10 15 Lys Glu Ala Glu 2011 20 PRT Artificial Sequence Synthetic polypeptide 11 Glu Val Thr GluGlu Glu Glu Thr Val Pro Leu Lys Thr Leu Glu Ala 1 5 10 15 Met Ile AspGlu 20 12 413 PRT Artificial Sequence Synthetic polypeptide 12 Ile AlaGly Pro Glu Trp Leu Leu Asp Arg Pro Ser Val Asn Asn Ser 1 5 10 15 GlnLeu Val Val Ser Val Ala Gly Thr Val Gly Thr Asn Gln Asp Ile 20 25 30 SerLeu Lys Phe Phe Glu Ile Asp Leu Thr Ser Arg Pro Ala His Gly 35 40 45 GlyLys Thr Glu Gln Gly Leu Ser Pro Lys Ser Lys Pro Phe Ala Thr 50 55 60 AspSer Gly Ala Met Ser His Lys Leu Glu Lys Ala Asp Leu Leu Lys 65 70 75 80Ala Ile Gln Glu Gln Leu Ile Ala Asn Val His Ser Asn Asp Asp Tyr 85 90 95Phe Glu Val Ile Asp Phe Ala Ser Asp Ala Thr Ile Thr Asp Arg Asn 100 105110 Gly Lys Val Tyr Phe Ala Asp Lys Asp Gly Ser Val Thr Leu Pro Thr 115120 125 Gln Pro Val Gln Glu Phe Leu Leu Ser Gly His Val Arg Val Arg Pro130 135 140 Tyr Lys Glu Lys Pro Ile Gln Asn Gln Ala Lys Ser Val Asp ValGlu 145 150 155 160 Tyr Thr Val Gln Phe Thr Pro Leu Asn Pro Asp Asp AspPhe Arg Pro 165 170 175 Gly Leu Lys Leu Thr Lys Leu Leu Lys Thr Leu AlaIle Gly Asp Thr 180 185 190 Ile Thr Ser Gln Glu Leu Leu Ala Gln Ala GlnSer Ile Leu Asn Lys 195 200 205 Asn His Pro Gly Tyr Thr Ile Tyr Glu ArgAsp Ser Ser Ile Val Thr 210 215 220 His Asp Asn Asp Ile Phe Arg Thr IleLeu Pro Met Asp Gln Glu Phe 225 230 235 240 Thr Tyr Arg Val Lys Asn ArgGlu Gln Ala Tyr Arg Ile Asn Lys Lys 245 250 255 Ser Gly Leu Asn Glu GluIle Asn Asn Thr Asp Leu Ile Ser Leu Glu 260 265 270 Tyr Lys Tyr Val LeuLys Lys Gly Glu Lys Pro Tyr Asp Pro Phe Asp 275 280 285 Arg Ser His LeuLys Leu Phe Thr Ile Lys Tyr Val Asp Val Asp Thr 290 295 300 Asn Glu LeuLeu Lys Ser Glu Gln Leu Leu Thr Ala Ser Glu Arg Asn 305 310 315 320 LeuAsp Phe Arg Asp Leu Tyr Asp Pro Arg Asp Lys Ala Lys Leu Leu 325 330 335Tyr Asn Asn Leu Asp Ala Phe Gly Ile Met Asp Tyr Thr Leu Thr Gly 340 345350 Lys Val Glu Asp Asn His Asp Asp Thr Asn Arg Ile Ile Thr Val Tyr 355360 365 Met Gly Lys Arg Pro Glu Gly Glu Asn Ala Ser Tyr His Ala Tyr Asp370 375 380 Lys Asp Arg Tyr Thr Glu Glu Glu Arg Glu Val Tyr Ser Tyr LeuArg 385 390 395 400 Tyr Thr Gly Thr Pro Ile Pro Asp Asn Pro Asp Asp Lys405 410 13 4 PRT Artificial Sequence Synthetic polypeptide 13 Xaa ValAsp Val 1 14 4 PRT Artificial Sequence Synthetic polypeptide 14 Val AspVal Xaa 1 15 5 PRT Artificial Sequence Synthetic polypeptide 15 Xaa ValAsp Val Xaa 1 5 16 5 PRT Artificial Sequence Synthetic polypeptide 16Val Asp Val Xaa Xaa 1 5

We claim:
 1. An isolated peptide obtained from streptokinase, or aderivative or analog thereof, which ameliorates cell death.
 2. Theisolated peptide according to claim 1 wherein said peptide comprises theamino acid motif: Val-Asp-Val.
 3. The isolated peptide according toclaim 1 having the sequence as set forth in SEQ. ID. No.
 1. 4. Theisolated peptide according to claim 1 having the sequence as set forthin SEQ. ID. No.
 2. 5. The isolated peptide according to clai 1 havingthe sequence as set forth in SEQ. ID. No.
 3. 6. The isolated peptideaccording to claim 1 having the sequence as set forth in SEQ. ID. No. 4.7. The isolated peptide according to claim 1 having the sequence as setforth in SEQ. ID. No.
 5. 8. The isolated peptide according to claim 1having the sequence as set forth in SEQ. ID. No.
 6. 9. The isolatedpeptide according to claim 1 having the sequence as set forth in SEQ.ID. No.
 7. 10. The isolated peptide according to claim 1 having thesequence as set forth in SEQ. ID. No.
 8. 11. The isolated peptideaccording to claim 1 wherein said peptide is a cyclic peptide.
 12. Theisolated peptide according to claim 1 wherein said peptide contains oneor more D amino acids.
 13. The isolated peptide according to claim 1wherein said peptide is further conjugated to one or more polypeptides.14. The isolated peptide according to claim 1 wherein said peptide isconjugated to a non-peptide moiety.
 15. The isolated peptide accordingto claim 14 wherein said non-peptide moiety is a sugar.
 16. The isolatedpeptide according to claim 1 wherein said peptide flrtler comprises anend group cap.
 17. The isolated peptide according to claim 16 whereinsaid end group cap is an ester.
 18. The isolated peptide according toclaim 16 wherein said end group cap is an amide.
 19. The isolatedpeptide according to claim 1 wherein said peptide is from 3 to 20 aminoacids in length.